JP2015139313A - converter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a converter device that alone enables preliminary charging of a main circuit capacitor without the other devices.SOLUTION: The converter device, configured to include switching elements connected in a bridge shape, comprises a rectification circuit that rectifies an AC voltage, a main circuit capacitor that smooths output of the rectification circuit, a drive circuit that drives the switching elements and a control circuit that controls operation of the drive circuit, where the control circuit is activated prior to activation of main circuits including the rectification circuit. The control circuit performs selectively either one of operations in a normal mode and in a preliminary charging mode when activating the main circuits. The normal mode is an operation mode for increasing gradually the on-period of the switching elements, and the change rate of the mode is a first set value. The preliminary charging mode is an operation mode for increasing gradually the on-period of the switching elements, and the change rate of the mode is a second set value smaller than the first set value.

Description

  Embodiments described herein relate generally to a converter device.

  For example, a device that operates by receiving power supply from an AC power source such as a commercial power source such as an inverter device is provided with a converter device that rectifies and smoothes an AC voltage supplied from the AC power source. The converter device includes a rectifier circuit in which diodes, thyristors, and the like are connected in a bridge shape, and a main circuit capacitor for smoothing the output of the rectifier circuit.

  When an electrolytic capacitor (for example, an aluminum electrolytic capacitor) that is often used as the main circuit capacitor is left in a non-energized state for a long period of time, its breakdown voltage decreases, leakage current increases, and the like, resulting in deterioration of characteristics. For this reason, it is recommended to periodically carry out energization (pre-charging, aging) for restoring the characteristics of the electrolytic capacitor. However, if a normal voltage (mounting voltage, rated voltage) is suddenly applied to an electrolytic capacitor that has not been energized for a long period of time, there is a risk that the electrolytic capacitor will fail due to deterioration of characteristics (such as a decrease in breakdown voltage). is there.

  As a method for preventing the occurrence of such a failure, for example, when performing preliminary charging, an AC voltage supplied from an AC power supply is not directly input to the converter device, but a single output transformer (for example, slidac ( And a method of connecting a resistor having a large resistance value so as to be interposed in series with the electrolytic capacitor. According to these methods, since the precharge can be performed by gradually increasing the voltage applied to the electrolytic capacitor, the above-described failure can be prevented.

  However, since it is difficult for all users who use inverter devices to prepare resistors and slidacs with high rated power (for example, several hundred W class), it is difficult to actually perform the above-described measures. It has become. In particular, in the case of an inverter device of a large capacity class, a slidac or the like that can cope with such a large capacity is required, which makes it difficult to cope with it.

JP 2012-186380 A

  In view of this, a converter device is provided that can precharge the main circuit capacitor by itself without requiring a separate device.

  The converter device of the present embodiment includes a switching element connected in a bridge shape, and includes a rectifier circuit that rectifies an AC voltage, a main circuit capacitor that smoothes the output of the rectifier circuit, a drive circuit that drives the switching element, and a drive circuit The control circuit which controls operation | movement of is provided. The converter device is configured such that the control circuit is activated prior to activation of the main circuit including the rectifier circuit. The control circuit selectively performs any one of the operations in the normal mode and the precharge mode when the main circuit is activated. The normal mode is an operation mode in which the ON period of the switching element is gradually increased, and the rate of change thereof is the first set value. The precharge mode is an operation mode in which the ON period of the switching element is gradually increased, and is a second set value whose change rate is smaller than the first set value.

This embodiment shows an electrical configuration diagram of an inverter device. External view schematically showing front configuration of inverter device The figure which shows the voltage between phases at the time of performing phase control by normal mode The figure which shows the phase voltage at the time of performing the phase control by precharge mode Flow chart for switching operation mode of phase control at startup The figure which shows an example of the display content relevant to precharge mode FIG. 1 equivalent view showing a modification in which the power supply to the control circuit is changed

Hereinafter, an embodiment of a converter device will be described with reference to the drawings.
As shown in FIG. 1, the inverter device 1 includes a rectifier circuit 2, a drive circuit 3, a control circuit 4, a main circuit capacitor 5, an inverter circuit 6, a voltage detection circuit 7, a phase detection circuit 8, an operation panel unit 9, and a display monitor. Part 10 is provided.

  The rectifier circuit 2 rectifies a three-phase AC voltage supplied from, for example, an AC power source 11 that is a commercial power source. The rectifier circuit 2 has a configuration in which a thyristor 12 (corresponding to a switching element) is connected in a three-phase bridge. A drive signal is given from the drive circuit 3 to the gate of the thyristor 12. The drive circuit 3 drives the thyristor 12 according to the ignition control signal given from the control circuit 4. The main circuit capacitor 5 smoothes the output of the rectifier circuit 2, and is an electrolytic capacitor such as an aluminum electrolytic capacitor.

  The inverter circuit 6 has a configuration in which switching elements 13 such as IGBTs are connected in a three-phase bridge. The inverter circuit 6 is driven by a drive circuit (not shown), and the drive is controlled by the control circuit 4. The inverter circuit 6 converts a DC voltage supplied through power supply lines L1 and L2 to which each terminal of the main circuit capacitor 5 is connected into a three-phase AC voltage, and supplies the three-phase AC voltage to a motor M that is a driving target of the inverter device 1.

  The voltage detection circuit 7 detects the terminal voltage Vc of the main circuit capacitor 5 (the voltages of the power supply lines L1 and L2) and outputs a voltage detection signal Sa representing the detected value to the control circuit 4. The phase detection circuit 8 detects (estimates) the period and phase based on the zero-cross timing of the three-phase AC voltage. The phase detection circuit 8 outputs to the control circuit 4 a phase detection signal Sb representing the detection result of the period and phase of the three-phase AC voltage.

  The control circuit 4 controls the overall operation of the inverter device 1, and is mainly composed of a microcomputer including a CPU 4a, a ROM 4b, a RAM 4c, an A / D converter 4d, and the like. In this case, the control circuit 4 includes an RTC 4e (real time clock). The control circuit 4 obtains the cycle and phase of the AC voltage based on the phase detection signal Sb, and controls the ignition timing (ignition timing) of the thyristor 12 constituting the rectifier circuit 2 based on the result (phase control). ).

  The rectifier circuit 14 rectifies and outputs a three-phase AC voltage supplied from the AC power supply 11. The power supply input terminal of the control power supply circuit 15 is supplied with the output voltage of the rectifier circuit 14 and the output voltage of the rectifier circuit 2 is supplied through the power supply lines L1, L2 and the diode 16 in the forward direction. . The control power supply circuit 15 operates in response to the supply of the DC voltage output from the rectifier circuit 14 or the rectifier circuit 2, and generates a control power supply voltage Vdd obtained by stepping down the DC voltage. The control power supply voltage Vdd is supplied to the control circuit 4 as its power supply voltage.

  The operation panel section 9 (corresponding to setting means) is composed of a plurality of operation means (see FIG. 2) that can be operated by the user. A signal indicating the operation state of the operation panel unit 9 is given to the control circuit 4. The control circuit 4 detects an operation on the operation panel unit 9 based on a signal indicating the operation state, and executes a process corresponding to the operation. The display monitor unit 10 (corresponding to the display unit) displays various types of information related to the inverter device 1 (values of set parameters, operation states, information related to a precharge mode described later, etc.). The operation of the display monitor unit 10 is controlled by the control circuit 4.

  In the present embodiment, the rectifier circuit 2, the drive circuit 3, the control circuit 4, the main circuit capacitor 5, the voltage detection circuit 7, the phase detection circuit 8, the operation panel unit 9, the display monitor unit 10, etc. It is configured. The rectifier circuit 2, the main circuit capacitor 5, the inverter circuit 6 and the like constitute a main circuit 18.

  In the inverter device 1 configured as described above, the control circuit 4 is activated prior to activation of the main circuit 18. That is, when the inverter device 1 is started (when the main power is turned on), the control circuit 4 passes through the power supply path (the rectifier circuit 14) different from the power supply path (path through the rectifier circuit 2) to the main circuit 18. The operation is started (started up) in response to power supply from the route. When activated, the control circuit 4 starts phase control of the thyristor 12 constituting the rectifier circuit 2. Thereby, power supply from the rectifier circuit 2 to the subsequent stage is started, and the main circuit 18 is activated. When the main circuit 18 starts up and shifts to a steady state, power is supplied to the control circuit 4 from the rectifier circuit 2 through the power supply lines L1 and L2 and the diode 16.

  FIG. 2 is an external view schematically showing a front configuration of the inverter device. As shown in FIG. 2, a control panel unit 21 including an operation panel unit 9 and a display monitor unit 10 is provided on the front surface of the inverter device 1. The operation panel unit 9 includes an operation knob 22 and an operation key group 23. The operation knob 22 is configured to be rotatable, and is configured to be able to be pressed in the direction of the rotation axis and on the housing side of the inverter device 1. The operation key group 23 includes a LOCREM key 23a, a RUN key 23b, a MODE key 23c, and a STOP key 23d, all of which are constituted by push switches.

  The display monitor unit 10 includes a numerical display 24 and a display lamp group 25. The numerical display 24 has a configuration in which four 7-segment LEDs (with a decimal point) are provided, and can display four-digit alphanumeric characters. The display lamp group 25 includes an S lamp 25a, a% lamp 25b, an Hz lamp 25c, a RUN lamp 25d, an AM lamp 25e, and a MON lamp 25f, all of which are constituted by LEDs. The S lamp 25a, the% lamp 25b, and the Hz lamp 25c are provided to display the unit of numerical values displayed on the numerical display 24. The RUN lamp 25d, the AM lamp 25e, and the MON lamp 25f are provided to display the operation state, the operation mode, and the like of the inverter device 1.

  Next, phase control of the thyristor 12 by the control circuit 4 will be described with reference to FIGS. 3 and 4 show only one set of interphase voltages among the three-phase AC voltages, the same applies to the other interphase voltages. The control circuit 4 controls the output voltage of the rectifier circuit 2 by controlling the ignition timing of each cycle of the thyristor 12, that is, the ratio of the on time for each cycle. The control circuit 4 has the following two operation modes when performing such phase control. A method for switching each operation mode will be described later.

“1” Normal Mode Phase control in the normal mode is performed to suppress an inrush current to the main circuit capacitor 5 at the time of normal power-on. In this case, as shown in FIG. 3, the control circuit 4 gradually changes the phase when the thyristor 12 is fired from 180 degrees to 90 degrees when the main circuit 18 is activated. Specifically, the control circuit 4 decreases the phase at the time of firing of the thyristor 12 by 5 degrees every cycle. In other words, the control circuit 4 gradually increases the ON period of the thyristor 12 every cycle. Note that the increase rate (change rate) of the ON period at this time corresponds to the first set value. In this case, assuming that the frequency of the AC power supply 11 is 60 Hz, it takes 0.3 seconds (= (90/5) × (1) until the phase when the thyristor 12 is fired reaches 180 degrees to 90 degrees. / 60)).

  That is, in this case, the main circuit capacitor 5 is charged over a time of 0.3 seconds. It should be noted that the charging time of the main circuit capacitor 5 in the normal mode (the amount of change per cycle of the phase when the thyristor 12 is ignited = 5 degrees) is the capacitance of the main circuit capacitor 5 used and the current of the thyristor 12. What is necessary is just to change suitably according to circuit characteristics, such as a rating. In this case, since the phase for each cycle is changed linearly, the rate of increase of the terminal voltage Vc is large immediately after the start of charging, and the rate of increase gradually decreases with time. This is the same operation as the step response of the capacitor in the RC circuit.

  As a result of such phase control in the normal mode, an inrush current to the main circuit capacitor 5 at the start-up of the apparatus is suppressed. Therefore, according to the configuration of the present embodiment, the circuit for suppressing the inrush current (resistor, relay, etc.) can be omitted, and the device can be reduced in size and the cost can be reduced accordingly. There is. Such merit becomes more useful as the capacity of the inverter device 1 is larger.

“2” Pre-charging mode (Aging Mode)
Phase control in the precharge mode is performed to restore the characteristics of the main circuit capacitor 5. Also in this case, as shown in FIG. 4, the control circuit 4 gradually changes the phase when the thyristor 12 is fired from 180 degrees to 90 degrees when the main circuit 18 is activated. However, in this case, specifically, the control circuit 4 decreases the phase at the time of firing of the thyristor 12 by 0.5 degrees every cycle. Note that the increase rate (change rate) of the ON period at this time corresponds to the second set value, and the value is smaller than the first set value. In this case, assuming that the frequency of the AC power supply 11 is 60 Hz, it takes 3 seconds (= (90 / 0.5) × (1) until the phase when the thyristor 12 is fired reaches from 180 degrees to 90 degrees. / 60)).

  That is, in this case, the main circuit capacitor 5 is charged over a period of 3 seconds. The charging time of the main circuit capacitor 5 in the preliminary charging mode may be longer than the charging time (0.3 seconds) in the normal mode described above. In this case, the charging time is set to a value based on the following reason. Is set.

In other words, as a conventional method of performing precharging to restore the characteristics of an electrolytic capacitor that exists as a single unit without being incorporated in a device, a resistor having a resistance value of about 1 kΩ is connected in series to the electrolytic capacitor. And a method of applying a rated voltage. According to this method, the charging current to the electrolytic capacitor is suppressed by increasing the time constant in the RC circuit, and as a result, charging is performed over a longer time than usual. In this case, according to the law of step response, the time τ [s] required for the electrolytic capacitor to be charged to 63.2% is as shown in the following (1). However, the capacitance value of the electrolytic capacitor is C, and the resistance value of the resistor is R.
τ = R × C (1)

  The time required for the electrolytic capacitor to be charged to almost 100% is about 3 to 5 times the time τ. In the present embodiment, the charging is performed in the same time (= τ × (3 to 5)) as the case where the preliminary charging for restoring the characteristics of the electrolytic capacitor existing alone is performed. The charging time of the main circuit capacitor 5 in the preliminary charging mode (the amount of change per cycle of the phase when the thyristor 12 is fired = second set value) is set.

  Now, when charging is performed while gradually increasing the terminal voltage Vc of the main circuit capacitor 5 by the phase control in the precharge mode, the characteristics are somewhat recovered, but then until the characteristics are completely recovered. Requires a certain period (for example, 5 hours). The main circuit capacitor 5 has a large amount of internal heat generation due to an increase in leakage current until the characteristic is completely recovered. Therefore, it is necessary to prevent normal operation during this period.

  Therefore, in this embodiment, a normal driving operation is performed during a predetermined period (hereinafter referred to as an operation unacceptable period) after the main circuit capacitor 5 is charged to 100% by phase control in the precharge mode. There is no such thing. Specifically, when the phase control period in the precharge mode ends, the control circuit 4 is given a signal related to the driving operation from the operation panel unit 9 until the time when the operation unacceptable period elapses. Even if it does, the process regarding it is not performed (driving operation is not received).

  Although illustration is omitted, a change-over switch for switching a plurality of functions is arranged in the vicinity of the control terminal block of the inverter device 1, and one of them is a change-over switch for switching an operation mode in phase control. Yes. In this case, the changeover switch is a slide switch having three contacts, and each contact corresponds to “ON1”, “ON2”, and “OFF” described later. Moreover, the parameter of the inverter apparatus 1 is provided with a switching parameter for setting whether or not to automatically switch the operation mode in the phase control. According to such a configuration, the user can manually switch the operation mode by operating the changeover switch. Further, the user can set whether or not to automatically switch the operation mode by setting a switching parameter by an operation using the operation panel unit 9 or the like.

Next, how the operation mode in the phase control is switched when the inverter device 1 is started will be described with reference to the flowchart of FIG.
When the main power is turned on (start), the control circuit 4 is activated and checks the contact state of the changeover switch (S1). When the contact of the changeover switch is “ON1”, the control circuit 4 executes phase control in the precharge mode (S5).

  On the other hand, when the contact of the changeover switch is “ON2”, the control circuit 4 detects an elapsed period that has elapsed without being charged since the main circuit capacitor 5 is discharged, and the elapsed period is the specified period ( For example, phase control in the preliminary charging mode or the normal charging mode is executed based on whether or not it is two years or more. The elapsed period is considered to be approximately the same as the period from the previous power-off to the current power-on. Therefore, the control circuit 4 automatically switches the operation mode as follows using the RTC 4e (the calendar function).

  That is, the control circuit 4 refers to the RTC 4e to determine the elapsed period from the previous power-off to the current power-on (S3), and determines whether the elapsed period is equal to or longer than the specified period (S4). ). When the control circuit 4 determines that the elapsed period is equal to or longer than the specified period (S4: YES), the control circuit 4 executes phase control in the precharge mode (S5). If the control circuit 4 determines that the elapsed period is less than the specified period (S4: NO), the control circuit 4 executes phase control in the normal mode (S6).

  On the other hand, when the contact of the changeover switch is “OFF”, the control circuit 4 confirms the setting of the changeover parameter (S2). When the switching parameter is set to OFF (NO), the control circuit 4 executes phase control in the normal mode (S6). On the other hand, when the switching parameter is set to ON (YES), the control circuit 4 determines whether or not the elapsed period is equal to or longer than the specified period, as in the case where the above-described switching switch is “ON2”. Based on (S3 and S4), phase control in the precharge mode or the normal mode is executed (S5 or S6).

  Next, a method for displaying information related to the precharge mode will be described with reference to FIG. In the following description, the time elapsed from the start of charging of the main circuit capacitor 5 to the current time is referred to as “elapsed time”, and the expected time required from the current time to completion of charging is referred to as “remaining time”. Call it.

  During the period when the phase control in the precharge mode is performed and the terminal voltage Vc of the main circuit capacitor 5 is increasing (about 3 seconds), the AM lamp 25e is lit on and the progress of charging the main circuit capacitor 5 Is displayed (see FIG. 6A or 6B). In the case of FIG. 6A, the remaining time (for example, 1.2 seconds) is displayed as the progress of charging. In this case, a numerical value of “1.2” is displayed by the 7-segment LED, and an S lamp 25a for indicating a unit of “second (s)” is lit.

  On the other hand, in the case of FIG. 6B, the current charged ratio is displayed as the charging progress. The charged ratio of the main circuit capacitor 5 can be expressed as follows based on the phase when the thyristor 12 is fired (hereinafter also referred to as phase angle). That is, the state of charge advances as the phase angle changes from 180 degrees to 90 degrees. Therefore, the charged ratio is 0% when the phase angle is 180 degrees, and thereafter, the charged ratio increases as the phase angle decreases, and the charged ratio is 100 when the phase angle is 90 degrees. %.

  In this case, the numerical value “60” is displayed by the 7-segment LED, and the% lamp 25b for indicating “%” is lit on. Note that the elapsed time (for example, 1.8 seconds) may be displayed as the progress of charging. The display in that case may be performed in the same manner as in FIG. Moreover, you may change so that the ratio (for example, 40%) of the uncharged at the present time may be displayed as a charge progress condition. The uncharged ratio of the main circuit capacitor 5 can be expressed based on the phase angle, similar to the charged ratio. The display in that case may be performed in the same manner as in FIG.

  When charging of the main circuit capacitor 5 is completed by the phase control in the preliminary charging mode and the operation shifts to the above-described operation unacceptable period, the AM lamp 25e changes to blinking display (see FIG. 6C). At this time, a waiting time (for example, 600 seconds) until the operation acceptance unavailable period ends is displayed by the same method as in FIG. 6A (see FIG. 6C). In the present embodiment, since the operation unacceptable period is, for example, 5 hours (= 18000 seconds), the waiting time cannot be displayed from the beginning to the end by the 4-digit 7-segment LED. Therefore, 9999 seconds are continuously displayed during a period in which the waiting time is 9999 seconds or more, and the actual waiting time is displayed when the waiting time is 9998 seconds or less.

  However, the display related to the time described above may be changed as follows. That is, the unit of time (S: second, M: minute, H: time) is displayed by the lowest digit (the rightmost digit in FIG. 6) of the four-digit 7-segment LED, and the S lamp 25a is displayed. Always off. Then, the time is displayed by the other three digits (three digits from the left in FIG. 6). For example, when “4.5 hours” is displayed, “4.50H” is displayed. In this way, for example, the waiting time until the operation unacceptable period ends can be displayed from the beginning to the end. In addition, if it is not necessary to display the time very strictly, it is not necessary to display the numerical value by the second 7-segment LED from the right.

  As described above, the control circuit 4 uses the terminal voltage of the main circuit capacitor 5 in addition to the normal mode for suppressing the inrush current to the main circuit capacitor 5 as the phase control operation mode when the main circuit 18 is started. There is a precharge mode in which Vc is raised more slowly than in the normal mode. Therefore, when the device is started in a state where the characteristics of the main circuit capacitor 5 are considered to be deteriorated, such as when the inverter device 1 has not been used for a long period of time, phase control in the precharge mode is performed. Thus, it is possible to restore the characteristics of the main circuit capacitor 5 while preventing damage due to a sudden characteristic change. Therefore, according to the present embodiment, precharging (aging) for restoring the characteristics of the main circuit capacitor 5 can be performed by a single device without separately preparing a device such as a slidac.

  Further, in the inverter device 1, whether or not to perform phase control in the normal mode when the main circuit 18 is started (switching parameter: OFF) is automatically determined by setting the switching parameter (setting by software). Whether to perform phase control (switching parameter: ON) can be switched. Since such setting of the switching parameter can be performed by an operation using the operation panel 9, there is an advantage that the operation can be simplified. If the switching parameter is set to ON, when the main circuit 18 is activated, if the elapsed period from the previous power-off is equal to or longer than the specified period, the activation in the precharge mode is performed. It is possible to automatically recover the characteristics of the main circuit capacitor 5 in a state where there is a high possibility of the failure.

  However, it is necessary to set the switching parameter during the operation of the inverter device 1. Therefore, after the power is turned off with the switching parameter set to OFF, the switching parameter setting cannot be changed if it has not been used for a long period of time (leaved). It will operate in normal mode. However, in the inverter device 1, whether the operation mode is determined based on the setting of the switching parameter when the main circuit 18 is activated (switching switch: OFF) or preliminary charging is performed also by the setting of the switching switch provided near the control terminal block. It is possible to switch whether phase control is performed in the mode (changeover switch: ON1) or whether appropriate mode is automatically determined to perform phase control (changeover switch: ON2). Therefore, even when the switching parameter setting is OFF, or the power is turned off without knowing the switching parameter setting and then left for a long period of time, at the first startup after that, Since the user can start in the desired operation mode by switching the changeover switch, the convenience is improved.

  For example, if the elapsed time from the previous power-off to the present time is extremely long (2 years or more) and the main circuit capacitor 5 is clearly deteriorating, the user switches the changeover switch to ON1. After that, the device may be activated. Then, since the main circuit 18 is reliably started in the precharge mode, the characteristics of the main circuit capacitor 5 that is highly likely to be deteriorated can be appropriately restored. In addition, if it is not possible to determine whether or not to start in the precharge mode because the elapsed time is unclear, the user can start the device after switching the changeover switch to ON2. That's fine. Then, as in the case where the switching parameter is set to ON, when the main circuit 18 is activated, the activation in the precharge mode is performed when the elapsed period from the previous power-off is equal to or longer than the specified period. Therefore, it is possible to automatically recover the characteristics of the main circuit capacitor 5 that is likely to be deteriorated.

  The control circuit 4 detects an elapsed period that has elapsed between the main circuit capacitor 5 being discharged and being charged using the calendar function of the RTC 4e. In this way, since the detection accuracy of the elapsed period is improved, preliminary charging can be performed at a more appropriate timing. In addition, when the preliminary charging mode is being performed, a display indicating that preliminary charging is being performed (lighting display of the AM lamp 25e) and a progress status of charging (elapsed time, remaining time, etc.) are displayed. It has become. In addition, in the operation unacceptable period after the main circuit capacitor 5 is charged by the phase control in the precharge mode, a display indicating that the operation is not acceptable (blink display of the AM lamp 25e) and the operation acceptance. The waiting time until the impossible period ends is displayed. In this way, since the user can appropriately grasp the current operation status and the like based on the display content of the display monitor unit 10, the convenience is improved.

(Other embodiments)
The rectifier circuit 2 may be configured to include a switching element connected in a bridge shape, and may be configured to include, for example, a GTO (gate turn-off thyristor). In that case, the turn-on timing may be controlled in the same manner as in the above-described embodiment, and the turn-off timing may be fixed to a predetermined timing (for example, zero-cross timing). Or you may change an ON period similarly to the said embodiment by controlling each timing of turn-on and turn-off.

  The method (setting means) for setting the operation mode at the time of starting the main circuit 18 may be changed as follows. For example, setting by either one of the switching parameter and the switching switch may be omitted. In the above embodiment, when the apparatus is started, the setting of the changeover switch is first confirmed, and then the setting of the changeover parameter is confirmed (priority of the changeover switch). It may be changed to confirm the setting of the switching parameter and then confirm the setting of the switching switch (switching parameter priority). Also, the “ON2” setting that automatically determines the optimum operation mode among the settings by the changeover switch may be omitted. In this case, a slide switch having two contacts may be employed as the changeover switch.

The display content of the information related to the preliminary charging mode is not limited to the content shown in FIG. 6 and can be changed as appropriate as long as it indicates information regarding the progress of the operation. In addition, when performing the preliminary charging mode, display of information related thereto may be omitted.
In the inverter device 1, when there is another capacitor connected between the power supply lines L 1 and L 2, not only the main circuit capacitor 5 but also the capacitance of the capacitor is considered (based on the combined capacitance value). ), The firing timing of the thyristor 12 in the phase control may be determined.

  About the structure regarding the electric power supply with respect to the control circuit 4, if the control circuit 4 starts before the main circuit 18 starts, it can change suitably. For example, the diode 16 may be omitted. In this case, the power supply input terminal of the control power supply circuit 15 and the power supply line L1 are disconnected (open). Even after the main circuit 18 is activated and shifts to a steady state, the control circuit 4 is supplied with power from the rectifier circuit 14.

Further, a switch 31 (for example, a relay) that opens and closes the power supply path from the rectifier circuit 14 to the control power supply circuit 15 may be provided as in the inverter device 1A shown in FIG. In this case, the switch 31 is turned on until charging of the main circuit capacitor 5 is completed (until shifting to a steady state). As a result, power is supplied from the rectifier circuit 14 to the control circuit 4. Then, after the charging of the main circuit capacitor 5 is completed (after shifting to a steady state), the switch 31 is turned off. As a result, power is supplied to the control circuit 4 from the rectifier circuit 2 through the power supply lines L1 and L2 and the diode D16.
The converter device 17 can be applied not only to the inverter device 1 but also to various devices and devices that operate by receiving power supply from an AC power supply.

As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.
These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawing, 2 is a rectifier circuit, 3 is a drive circuit, 4 is a control circuit, 4e is an RTC (real time clock), 5 is a main circuit capacitor, 7 is a voltage detection circuit, 9 is an operation panel section (setting means), 10 is A display monitor unit (display unit), 12 is a thyristor (switching element), 17 is a converter device, and 18 is a main circuit.

Claims (7)

A rectifier circuit that includes switching elements connected in a bridge shape and rectifies an AC voltage;
A main circuit capacitor for smoothing the output of the rectifier circuit;
A drive circuit for driving the switching element;
A control circuit for controlling the operation of the drive circuit;
With
Prior to activation of the main circuit including the rectifier circuit, the control circuit is activated,
The control circuit is an operation mode in which the ON period of the switching element is gradually increased when the main circuit is started up, and an operation in a normal mode in which the change rate is the first set value; and One of the operations in the precharge mode in which the ON period of the switching element is gradually increased and the rate of change thereof is a second set value smaller than the first set value is selectively performed. The converter apparatus characterized by the above-mentioned. A setting means for a user to set an operation mode at the time of starting the main circuit;
2. The converter device according to claim 1, wherein the control circuit performs the operation in the preliminary charging mode when the setting unit is set to perform the operation in the preliminary charging mode. 3.   The converter device according to claim 2, wherein the setting unit sets the operation mode by setting a parameter.   The converter device according to claim 2, wherein the setting unit sets the operation mode according to a state of a change-over switch that can be operated by a user. The control circuit includes:
With a real time clock,
The elapsed time that has elapsed without being charged since the main circuit capacitor is discharged is detected using the real-time clock, and when it is determined that the elapsed period is equal to or longer than a predetermined specified period, The converter device according to claim 1, wherein the converter device performs the following operations. It has a display for displaying various information,
6. The converter device according to claim 1, wherein when the operation in the precharge mode is performed, the control circuit displays information on a progress status of the operation on the display unit. 6. . The switching element is a thyristor;
The converter device according to claim 1, wherein the control circuit changes the ON period by controlling an ignition timing of the thyristor.

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